Sealing device for linear guide apparatus

ABSTRACT

In a linear guide apparatus including an axially extending guide rail, a slider engaged with the guide rail, and a plurality of rolling elements loaded into the slider, the linear guide apparatus further includes a sealing device fixed to the slider in slidable contact with the guide rail for sealing a clearance existing between the guide rail and the slider, in which the sealing device includes a lubricant-containing polymer member formed of a synthetic resin containing a lubricant, and having a contact portion contacting with the guide rail to surround the guide rail, both wing portions, a connecting portion connecting the wing portions to be C-shaped substantially, and a pair of first recesses formed in the respective wing portions for fixing the lubricant-containing polymer member to the slider; a first plate member fitted to the lubricant-containing polymer member opposed to the slider; and a pair of first cylindrical members inserted to the respective first recesses.

This is a continuation of application Ser. No. 09/371,493 filed Aug. 10,1999 now U.S. Pat. No. 6,257,765, which is a continuation of applicationSer. No. 08/678,765 now U.S. Pat. No. 6,019,513, filed Jul. 11, 1996,the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a linear guide apparatus, and moreparticularly relates to a sealing device for a linear guide apparatuswhich lubricant can be stably fed to the rolling elements over a longperiod of time.

Further, the present invention relates to a linear guide apparatus, andmore particularly relates to a linear guide apparatus, to the lipportion of the sealing device of which lubricant can be automaticallyfed, so that the life of the sealing device can be prolonged.

A first conventional example will be described as follows. An example ofthe conventional linear guide apparatus, which is commonly used, isshown in FIG. 37. This conventional linear guide apparatus includes: aguide rail 1 extending in the axial direction, on the outer surface ofwhich a rolling element rolling groove 3 is formed; and a slider 2incorporated to the guide rail 1 in such a manner that the slider 2strides the guide rail 1. The slider 2 is composed of a slider body 2Aand end caps 2B attached to both ends of the slider body 2A. On innerside surfaces of both wing portions 4 of the slider body 2A, there areprovided rolling element rolling grooves (not shown in the drawing)which are opposed to the rolling element rolling groove 3 formed on theguide rail 1. Also, in the slider body 2A, there are provided rollingelement returning paths (not shown) which penetrate thick portions ofthe wing portions of the slider body 2A. On the other hands, the endcaps 2B have curved paths (not shown) which communicate the rollingelement rolling grooves of the slider body 2A with the rolling elementreturning paths formed in parallel to the rolling element rollinggrooves. In this way, a circulation circuit of the rolling elements isformed by the rolling element rolling grooves, the rolling elementreturning paths and the curved paths formed on both sides. For example,a large number of rolling elements composed of steel balls are chargedinto the circulation circuit in which the rolling elements arecirculated.

The slider 2 incorporated to the guide rail 1 is smoothly moved alongthe guide rail 1 when the rolling elements are rolling in both rollingelement grooves which are opposed to each other. While the rollingelements are rolling in this way, they circulate endlessly in therolling element circulation passages formed in the slider.

As a sealing device to seal an opening between the slider 2 and theguide rail 1 for the purpose of dust protection, as shown in FIG. 38,there are provided side seals 5 on both ends (end faces of the end caps2B), and also there is provided an under seal 6 on the lower surface ofthe slider 2. Conventionally, these seals are made of rubber such as NBR(acrylonitrile butadiene rubber). In this connection, reference numeral7 in FIG. 37 is a grease nipple.

A second conventional example of the linear guide apparatus is disclosedin Unexamined Japanese Patent Publication No. Hei. 6-346919 previouslyproposed by the present applicant. A third conventional example of thelinear guide apparatus is disclosed in Unexamined Japanese PatentPublication No. Hei. 7-35146 previously proposed by the presentapplicant.

The second conventional example will be described as follows. Betweenthe outer surface of the guide rail and the inner surface of the slidermoving along the guide rail, there is provided a seal device having aseal lip portion made of rubber or synthetic resin containing lubricant.The seal lip portion comes into contact with an outer surface of theguide rail and seals a gap formed between the inner surface of theslider and the outer surface of the guide rail. Since the seal lipportion of the seal device is made of rubber or synthetic resincontaining lubricant so that the seal lip portion has a self-lubricatingproperty, the lubricant contained in the seal gradually oozes out and isautomatically fed to a frictional surface of the seal portion.Therefore, the abrasion of the seal lip portion can be suppressed.

The third conventional example will be described as follows. At least aportion of the layer made of rubber or synthetic resin and a portion ofthe layer made of rubber or synthetic resin containing lubricant areoverlapped and integrally joined. At least, on the layer of rubber orsynthetic resin containing lubricant, there is formed a seal lip portionwhich comes into contact with an outer surface of the guide rail so asto seal a gap formed between the inner surface of the slider and theouter surface of the guide rail. Since the seal lip portion also has aself-lubricating property in this third conventional example, lubricantcontained in the seal itself gradually oozes out and is fed to africtional surface of the seal, so that the abrasion of the lip portioncan be suppressed. Since the layers are overlapped as described above inthe third conventional example, it is possible to provide the followingadvantages. When the number and thickness of the overlapped layers areappropriately determined, the mechanical strength of the seal lipportion can be arbitrarily set in accordance with the use of the linearguide apparatus.

As shown in FIGS. 52 to 53B, the sealing device of the secondconventional example is described as follows. Lubricant is made to oozefrom a surface of the guide rail 1 by the action of contact resistanceof the seal 5. Accordingly, there is provided no relief 73 as shown inFIG. 53A in the contact portion 71 shown in FIG. 53B where the seal 5comes into contact with the guide rail 1, but an area of the portionwhere the seal 5 comes into contact with the guide rail 1 is increased.Further, there is formed a recessed groove 72 in the contact portion 71where the seal 5 comes into contact with the guide rail 1, so that theportion 71 is divided into two portions. Then the thus divided portionsare contacted with the guide rail 1 by two steps. Therefore, theintrusion of foreign objects can be prevented by the contact of twosteps better than the contact of one step. Further, lubricant can beheld by the recessed groove 72, so that the sliding property of the seal5 can be enhanced.

However, the above conventional linear guide apparatus has the followingdisadvantages.

As the slider 2 runs along the guide rail 1, a quantity of greasepreviously charged inside the slider 2 is decreased. Therefore, thelubrication between the lip portion of the side seal 5 and the guiderail 1 becomes poor, and also the lubrication between the lip portion ofthe under seal 6 and the guide rail 1 becomes poor. Due to the poorlubrication, the lip portions gradually wears away. Due to the progressof abrasion, the sealing property is deteriorated, and foreign objectssuch as cutting chips enter the inside of the slider 2, which shortensthe life of the linear guide apparatus in some cases.

When the slider 2 runs and the rolling elements roll, grease can be fedto the rolling element rolling groove 3 of the guide rail 1 via therolling elements. Accordingly, the abrasion is relatively small in aportion of the lip which comes into contact with the rolling elementrolling groove 3. On the other hand, the abrasion tends to increase in aportion of the lip which comes into contact with an upper surface of therail to which no grease is fed because of poor lubrication. Due to theforegoing, the lip portion wears away and damaged. In this way, the lifeof the linear guide apparatus is shortened.

From this point of view, when the above second example and the third oneare adopted, the abrasion of the seal lip portion can be suppressedsince the seal lip portion has a self-lubricating property. However,even in the above conventional examples, the following problems may beencountered. A quantity of lubricant oozing from rubber or syntheticresin containing lubricant is not sufficient to lubricate the balls androllers which guide the movement of the slider of the linear guideapparatus, that is, it is difficult to maintain smooth rolling motionsof the rolling elements such as balls and rollers.

In the sealing device containing lubricant of the above secondconventional example or the third one, the seal lip portion is pressedagainst the guide rail only by the elasticity of the seal itself.Accordingly, it is possible to provide a sufficiently high pressingforce as a seal, however, it is impossible to provide a sufficientlyhigh pressing force as a lubricant feed unit.

Further, a shape of each portion of the guide rail 1 with which the seal11 comes into contact, for example, a shape of the ball rolling groove,the guide rail side surface or the upper surface of the guide rail iscomplicated, and further the seal 11 is attached being a littledisplaced. Therefore, it is difficult for the seal 11 to be positivelycontacted with each portion of the guide rail 1. Accordingly, asufficient quantity of lubricant can not be provided and the dustprotecting property is deteriorated. As a result, the lubricant in theslider 2 is widely diffused.

SUMMARY OF THE INVENTION

The present invention has been accomplished to solve problems caused ina conventional linear guide apparatus. An object of the presentinvention is to provide a linear guide apparatus in which the abrasionof a sealing device is reduced by directly feeding lubricant to the lipportion or by feeding lubricant via the guide rail, so that a highsealing property can be maintained in the linear guide apparatus over along period of time.

Another object of the present invention is to provide a linear guideapparatus in which lubricant can be fed at all times so as to maintain asmooth rolling motion of the rolling elements.

Still another object of the present invention is to provide a linearguide sealing device in which the seal can be positively contacted witheach portion while the seal precisely follows the shape of each portion.

The objects of the invention are achieved by a linear guide apparatuswhich includes: an axially extending guide rail having a first rollinggroove on its outer surface; a slider engaged with the guide rail andhaving a second rolling groove, rolling element return grooves andcurved grooves, the second rolling groove confronting the first rollinggroove, the rolling element return grooves being coupled to both endportions of the second rolling groove through the curved grooves,respectively; a plurality of rolling elements loaded into the slider tobe made circulatable through the second rolling groove, the curvedgrooves, and the rolling element return grooves; and a sealing devicefixed to the slider in slidable contact with the guide rail for sealinga clearance existing between the guide rail and the slider, the sealingdevice comprising: a lubricant-containing polymer member formed of asynthetic resin containing a lubricant, and having a contact portioncontacting with the guide rail to surround the guide rail, both wingportions, a connecting portion connecting the wing portions to beC-shaped substantially, and a first plate member fitted to thelubricant-containing polymer member in which the lubricant-containingpolymer member is interposed between the slider and the first platemember.

According to the invention, since a lubricant-containing polymer memberis arranged close to the lip portion of a side seal which is provided inthe sealing device, lubricant that has gradually oozed from thelubricant-containing polymer member is easily fed to the lip portion, sothat the lip portion can be stably lubricated over a long period oftime.

In addition, since at least a portion of the inner circumferentialsurface of the lubricant-containing polymer member comes into contactwith the outer circumferential surface of the guide rail, the lipportion can be fed with lubricant via the guide rail. Therefore, it ispossible to feed lubricant to the lip portion very stably. Accordingly,the abrasion of the lip portion can be minimized, and the sealingproperty of the sealing device can be maintained to be high over a longperiod of time.

Lubricant that has oozed from the lubricant-containing polymer member isalso fed to the rolling elements via the guide rail. Accordingly, evenwhen grease is exhausted from the apparatus for some reasons, thelubricant that has oozed out from the lubricant-containing polymermember functions as a lubricant of the linear guide apparatus itself.

Especially when the lubricant-containing polymer member is interposedbetween the slider end face and the side seal, the leakage of greasefrom the device can be reduced. The reason is described as follows.Conventionally, the lip portion of the sealing device gets rolled upduring a normal reciprocating motion of the slider. At this time, greaseleaks out from the device. On the other hand, according to theinvention, the lubricant-containing polymer member is interposed betweenthe slider end face and the side seal. Therefore, the lip portion isdifficult to get rolled up, and the leakage of grease from the devicecan be reduced. In the case where the side seal is composed of apolyurethane rubber member containing grease which works as lubricant,the abrasion of the lip portion of the sealing device can be furtherreduced.

Further, according to the invention, when lubricant oozes from thelubricant-containing member which strides the guide rail, thelubricant-containing member shrinks by itself, so that a distancebetween both wing portions of the lubricant-containing member, which isarranged in a C-shape, is reduced, and further the inside faces of bothwing portions of the lubricant-containing member, that is, the facesopposed to the side faces of the guide rail, are pushed against theguide rail. Therefore, the lubricant-containing member comes intocontact with the guide rail at all times. Due to the pushing forcegenerated by the pushing means, no gap is formed between the guide railand the lubricant-containing member irrespective of errors caused in themanufacturing process. Therefore, the lubricant oozing from thelubricant-containing member can be stably fed to the guide rail.Particularly, the shape of the bottom surface of the C-shapedlubricant-containing member is formed into a predetermined shape of anarc. Therefore, even when the lubricant-containing member is deformed bythe pushing force of the pushing means so that both wing portions arepressed against the guide rail, the shape of the arc on the bottomsurface is put into a horizontal condition. Consequently, thelubricant-containing member stably comes into contact with the guiderail.

Moreover, according to the invention, a plurality of cutout portions areformed in a portion of the seal lip which comes into pressure contactwith an outer surface of the guide rail. Therefore, the seal lip inwhich a plurality of cutout portions are formed can be contacted withthe outer surface of the guide rail, the shape of which is complicated.In this way, the seal lip can easily follow the shape of the guide rail.Even when the lubricant feed device is dislocated in the assemblingprocess, the seal lip having the cutout portions is deformed, so thatthe dislocation can be absorbed, and no gap is formed between the seallip portion and the guide rail.

When a plurality of cutout portions are formed in the seal lip portion,the contact area of the seal lip portion with the guide rail can beincreased, so that a quantity of lubricant oozing from the seal lipportion can be increased. When the seal lip portion is provided with aplurality of cutout portions, a space in which the lubricant is held canbe increased as compared with a conventional arrangement. Therefore, thesliding property of the seal lip portion can be enhanced. Further, thenumber of the seal lip portions is increased as compared with aconventional arrangement, so that the intrusion of dirt and dust fromthe outside can be prevented, and the lubricant can be prevented fromdiffusing to the outside.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the linear guide apparatus of a firstembodiment of the present invention;

FIG. 2 is a perspective view showing a condition in which each member ofa sealing device is attached to the end portion of the linear guideapparatus;

FIGS. 3A and 3B are views showing an arrangement of thelubricant-containing member of the second embodiment;

FIGS. 4A and 4B are views showing an arrangement of the ring-shapedmember;

FIGS. 5A and 5B are views showing an arrangement of the ring-shapedmember;

FIG. 6 is a side view of the lubricant-containing member in a conditionthat the ring-shaped member is attached;

FIG. 7 is a front view of the lubricant-containing member which stridesa guide rail;

FIGS. 8A and 8B are schematic illustrations showing the mode ofoperation;

FIG. 9 is a front view showing an arrangement of thelubricant-containing member of a third embodiment of the presentinvention;

FIG. 10 is a schematic illustration showing the mode of operation of thethird embodiment;

FIG. 11 is a perspective view showing an attaching condition of eachmember of a sealing device of a fourth embodiment;

FIGS. 12A and 12B are views showing an arrangement of thelubricant-containing member of the fourth embodiment;

FIGS. 13A and 13B are views showing an arrangement of the elastic bodyof the fourth embodiment;

FIG. 14 is a schematic illustration of the mode of operation of thefourth embodiment;

FIG. 15 is a schematic illustration of the mode of operation of thefourth embodiment;

FIG. 16 is a front view of the lubricant-containing member of the fourthembodiment, wherein the view shows a condition in which the memberstrides the guide rail;

FIG. 17 is a side view of the lubricant-containing member of the fourthembodiment, wherein a ring-shaped member is attached to the member;

FIGS. 18A and 18B are views showing an arrangement of thelubricant-containing member of a fifth embodiment of the presentinvention;

FIGS. 19A and 19B are views showing an arrangement of thelubricant-containing member of a sixth embodiment of the presentinvention;

FIG. 20 is a view showing an arrangement of the elastic body of thesixth embodiment;

FIGS. 21A and 21B are schematic illustrations showing an assemblingcondition of the sixth embodiment;

FIG. 22 is a perspective view of the linear guide apparatus of the sixthembodiment;

FIG. 23 is a front view of the lubricant-containing member of a seventhembodiment of the present invention;

FIG. 24 is a view of the lubricant-containing member of an eighthembodiment of the present invention;

FIGS. 25A and 25B are views showing an arrangement of the elastic bodyof the eighth embodiment;

FIGS. 26A and 26B are schematic illustrations showing an assemblingcondition of the eighth embodiment;

FIG. 27 is a front view of the lubricant-containing member of a ninthembodiment of the present invention;

FIGS. 28A and 28B are views showing an arrangement of the elastic bodyof the ninth embodiment;

FIGS. 29A and 29B are schematic illustrations showing an assemblingcondition of the ninth embodiment;

FIGS. 30A and 30B are front views showing an arrangement of a tenthembodiment of the present invention;

FIGS. 31A to 31D are perspective views showing an eleventh embodiment ofthe present invention;

FIGS. 32A to 32C are perspective views showing variations of theeleventh embodiment;

FIG. 33 is a front view showing an arrangement of a twelfth embodimentof the present invention;

FIG. 34 is a perspective view of the lubricant-containing polymer memberof the first embodiment of the present invention;

FIG. 35 is a perspective view of the sleeve inserted into thelubricant-containing polymer member;

FIG. 36 is a perspective view showing an attaching condition of eachmember of a sealing device of the linear guide apparatus end portion;

FIG. 37 is a perspective view of the conventional linear guideapparatus;

FIG. 38 is a perspective view of the lower surface side of the linearguide apparatus shown in FIG. 37;

FIG. 39 is an overall perspective view of the side seal composing aportion of the sealing device according to a thirteenth embodiment ofthe present invention;

FIG. 40 is an enlarged cross-sectional view of the seal lip of the sideseal of the thirteenth embodiment;

FIG. 41 is a perspective view taken from the lower side of the linearguide apparatus of the thirteenth embodiment;

FIG. 42 is an enlarged cross-sectional view of the seal lip of the underseal of the thirteenth embodiment;

FIG. 43 is a schematic cross-sectional view for explaining a variationof the side seal of the thirteenth embodiment;

FIG. 44 is a schematic perspective view for explaining another variationof the side seal;

FIG. 45 is a partially enlarged view of the seal lip of the side sealshown in FIG. 44;

FIG. 46 is a schematic perspective view for explaining another variationof the side seal;

FIG. 47 is a partially enlarged view of the seal lip of the side sealshown in FIG. 46;

FIG. 48 is a schematic perspective view for explaining another variationof the side seal;

FIG. 49 is an enlarged cross-sectional view of the seal lip portion ofthe side seal shown in FIG. 48;

FIG. 50 is a schematic perspective view for explaining another variationof the side seal;

FIG. 51 is an enlarged cross-sectional view of the seal lip portion ofthe side seal shown in FIG. 50;

FIG. 52 is an overall perspective view of another conventional sideseal; and

FIGS. 53A and 53B are enlarged cross-sectional views of two types of theseal lip portion of the side seal shown in FIG. 52.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed explanations will be made below for the material of thelubricant-containing member of the present invention.

In the case of a member made of rubber in which lubricant is contained,for example, it is possible to use polyurethane rubber that has beencured under the condition that it contains grease.

Polyurethane rubber is a compound formed by the reaction ofpolyisocyanate and active hydrogen compound. Examples of usablepolyisocyanate are: tolylenediisocyanate, hexamethylene diisocyanate,and so forth.

Examples of usable active hydrogen compounds are: hydrocarbon such aspolybutadiene; polyether such as polyoxypropylene; long link activehydrogen compound such as castor oil, polyester and polycarbonate;polyhydroxy compound such as water and ethylene glycol; and short linkactive hydrogen compound such as aminoalcohol and polyamino compound.

An example of usable grease is common grease such as mineral oil lithiumsoap grease.

Next, the lubricant-containing member in which lubricant is contained insynthetic resin is formed as follows. Lubricant of paraffin hydrocarbonoil such as poly-α-olefin oil, ether oil such as naphthene hydrocarbonoil, mineral oil and dialkyl diphenyl ether oil, and ester oil such asester of phthalic acid is singly mixed with synthetic resin oralternatively mixed with synthetic resin in the form of mixed oil. Inthis case, the synthetic resin is selected from a group of polyolefinresins having the same chemical structure such as polyethylene,polypropylene, polybutylene and polymethyl pentene. Material obtained inthis way is subjected to injection molding so as to mold thelubricant-containing member. Various addition agents such as anantioxidant, rust preventive agent, antiabrasion agent, deforming agentand extreme pressure agent may be previously added into the lubricant.

In this case, a ratio of composition of the above lubricant-containingmember is as follows. With respect to the total weight, polyolefin resinis 20 to 80% by weight, and lubricant is 80 to 20% by weight. When thepolyolefin resin is smaller than 20% by weight, it is impossible toobtain a predetermined level of hardness or mechanical strength. Whenpolyolefin resin exceeds 80% by weight, that is, lubricant is smallerthan 20% by weight, a quantity of lubricant to be fed is decreased, sothat the abrasion reducing effect of the lip portion of the sealingdevice is deteriorated. Further, the polyolefin resin is preferably 20to 50% by weight and the lubricant is preferably 80 to 50% by weightbecause the supply of the lubricant increases so that it can furtherraises the abrasion reducing effect of the lip portion of the sealingdevice.

Basic structures of the above group of synthetic resins are the same andtheir average molecular weights are different from each other. Values ofthe average molecular weights are in a range from 1×10³ to 5×10⁶.Synthetic resin of relatively low molecular weight, the averagemolecular weight of which is 1×10³ to 1×10⁶, and synthetic resin ofextremely high molecular weight, the average molecular weight of whichis 1×10⁶ to 5×10⁶, are singly used, or used being mixed with each other,if necessary.

In order to enhance the mechanical strength of the lubricant-containingmember of the present invention, the following thermoplastic resins andthermosetting resin may be added to the above polyolefin resins.

Examples of usable thermoplastic resins are: polyamide, polycarbonate,polybutylene terephthalate, polyphenylene ID sulfide, polyether sulfone,polyether etherketone, polyamideimide, polystyrene, and ABS resin.

Examples of usable thermosetting resins are: unsaturated polyesterresin, urea formaldehyde resin, melamine resin, phenol resin, polyimideresin, and epoxy resin.

These resins may be singly used. Alternatively, these resins may be usedbeing mixed with each other.

In order to disperse polyolefin resin and other resins more uniformly,an appropriate compatibilizer may be added, if necessary.

In order to enhance the mechanical strength, a filler may be added.Examples of usable fillers are: calcium carbonate, magnesium carbonate,inorganic wiskers such as potassium titanate wiskers and aluminum boratewiskers, inorganic fiber such as glass fiber, asbestos and metallicfiber, and cloth woven from these fibers. Concerning inorganiccompounds, carbon black, graphite powder, carbon fiber, aramid fiber andpolyester fiber may be added.

In order to prevent the deterioration of polyolefin resin caused byheat, an age resistor such as N, N′-diphenyl-P-phenylenediamine, 2,2′-methylenebis (4-ethyl-6-t-butyl phenol) may be added. In order toprevent the deterioration of polyolefin resin caused by light, anultraviolet ray absorbing agent such as 2-hydroxy-4-n-octoxybenzophenone and 2-(2′-hydroxy-3′-third-butyl-5′-methyl-phenyl)-5-chlorobenzotriazole may be added.

In order to maintain the feeding capacity of lubricant, it is preferablethat a quantity of addition agent (polyolefin+compound except for oil)is not more than 20% by the weight of the overall material used formolding.

Next, referring to the accompanying drawings, a first embodiment of thepresent invention will be explained below.

As shown in FIG. 1, which is a perspective view of the linear guideapparatus of the first embodiment of the invention, the linear guideapparatus includes: a guide rail 1 extending in the axial direction, onthe outer surface of which rolling element rolling grooves 3A, 3B areformed; and a slider 2 incorporated to the guide rail 1 in such a mannerthat the slider 2 strides the guide rail 1.

The specific structure of the guide rail 1 is described as follows. Onthe ridge line where an upper surface 1 a of the guide rail 1 crossesboth side surfaces 1 b, one rolling element rolling groove 3A is formed,the section of which is a substantial ¼ arc, and the rolling elementrolling groove 3A extends in the axial direction of the guide rail 1. Atan intermediate position on both side surfaces of the guide rail 1, theother rolling element rolling groove 3B is formed, the section of whichis substantially semicircular. At the bottom of the rolling elementrolling groove 3B, there is formed a run-off-groove 3 a for a retainerto prevent the rolling elements from falling off when the slider 2 isnot incorporated to the guide rail 1.

An end cap 2B is a molding of synthetic resin manufactured by injectionmolding, and the section of the end cap 2B is a substantial C-shape. Asshown in FIG. 2, which is a perspective view showing an assemblingcondition of the end portion of the slider 2, on the outside of both endcaps 2B, there are provided a sealing device 8 including a reinforcingplate 10 which is a plate-shaped member, a lubricant-containing member11, and a side seal 12 which is a plate-shaped member, wherein they arearranged in the above order from the side of the end cap 2B and fixed tothe end cap 2B being stacked to each other.

The reinforcing plate 10 is a C-shaped steel plate, the outerconfiguration of which is the same as that of the end cap 2B. In bothwing portions 10A, 10B of the reinforcing plate 10, there are formedthrough-holes 10 a, 10 b through which attaching screws penetrate. In aconnecting portion 10C that connects both wing portions 10A and 10B,there is formed a through-hole 10 c through which a grease nipple isattached. In this connection, this reinforcing plate 10 is not contactedwith the guide rail 1.

The first embodiment of the present invention is shown in FIGS. 34 to 36in more detail. The sealing device 8 includes a side seal 50 which iscomposed in such a manner that a sheet of grease-containing polyurethanerubber is made to adhere onto a C-shaped steel plate, the outer shape ofwhich is substantially the same as that of the end cap 2B, oralternatively a sheet of NBR rubber is made to adhere onto a C-shapedsteel plate. An inside face of the C-shaped side seal 50 is formed intoa shape so that the side seal 50 can slidably come into contact with anupper face 1 a and an outer side face 1 b of the guide rail 1 so as toseal a gap between the slider 2 and the guide rail 1. However, in orderto positively seal the gap between the slider 2 and the guide rail 1,the size of the inner face of the side seal 50, which comes into contactwith the surface of the guide rail 1, is determined to be a littlesmaller than the size of the surface of the guide rail 1 by 0.1 to 0.2mm.

As shown in the perspective view of FIG. 36, the sealing device 8further includes a reinforcing plate 52 and a lubricant-containingpolymer member 51 which is interposed between the side seal 50 and thereinforcing plate 52 and which is formed into a substantial C-shapewhich is the same as the outer shape of the end cap 2B. The inside faceof the C-shape of the lubricant-containing polymer member 51 is formedin accordance with the sectional shape of the guide rail 1, and it isnot contacted with the upper face 1 a and the outer side face 1 b of theguide rail 1, or at least a portion of the inside face of the C-shape ofthe lubricant-containing polymer member 41 is slidably contacted withthe upper face 1 a and the outer side face 1 b of the guide rail 1.

In the lubricant-containing polymer member 51, there are formedthrough-holes 51 a, 51 b through which attaching screws penetrate whenthe lubricant-containing polymer member 51 is attached to the main body2A, and there is also formed a through-hole 51 c through which thegrease nipple 7 is attached. Into the through-holes 51 a, 51 b and 51 c,pipe-shaped sleeves 51A, 51B and 51C shown in FIG. 35 are inserted. Thegrease nipple 7 penetrates the inside of the sleeve 51C. In thisconnection, the length L₂ of these sleeves 51A, 51B, 51C is the same asthe thickness L₁ of the lubricant-containing polymer member 51, oralternatively the length L₂ of these sleeves 51A, 51B, 51C is made to bea little longer than the thickness L₁ of the lubricant-containingpolymer member 51 (by about 0.2 mm).

Outer diameters of the sleeves 51A, 51B are made to be larger than thediameters of the through-holes 50 a, 50 b of the side seal 50 and thediameters of the through-holes 52 a, 52 b of the reinforcing plate 52.Due to the foregoing arrangement, when the lubricant-containing polymermember 51 is interposed between the side seal 50 and the reinforcingplate 52 and fastened by the attaching screws 53 a, 53 b, the pushingforce is not given to the lubricant-containing polymer member 51, sothat the self-shrinking action of the lubricant-containing polymermember 51 can not be obstructed.

As shown in a perspective view of FIG. 36, the side seal 50, thelubricant-containing polymer member 51 and the reinforcing plate 52 ofthe sealing device 8 are integrally fixed to the main body 2A togetherwith the end cap 2B when the attaching screws 53 a, 53 b penetrate thethrough-holes 50 a, 50 b of the side seal 50, the through-holes 51 a, 51b of the lubricant-containing polymer member 51, and the through-holes52 a, 52 b of the reinforcing plate 52. In this connection, referencenumeral 50 c is a through-hole formed on the side seal 50 through whichthe grease nipple 7 is attached, and reference numeral 52 c is athrough-hole formed on the reinforcing plate 52 through which the greasenipple 7 is attached.

Next, the mode of operation of the first embodiment will be explained asfollows.

In the first embodiment, a gap formed between the opposed surfaces ofthe guide rail 1 and the slider 2 is sealed by the side seal 50.Therefore, unless the side seal 50 wears away, it is possible toperfectly prevent the entrance of dirt and dust into the gap from thefront and the rear of the slider 2.

When the slider 2 moves on the guide rail 1 fixed to the mount, whilethe rolling elements B are rolling in the load rolling element rollingpath 21 (22), they move in the slider moving direction at a speed lowerthan the moving speed of the slider and make a U-turn at the curved pathon one end side. After that, while the rolling elements B are rolling inthe rolling element return path 23 (24) in the reverse direction, theymake a reverse U-turn in the curved path on the other end side. Then,the rolling elements B return to the load rolling element rolling path21 (22). In this way, the rolling elements B circulate in the rollingpaths.

When the linear guide apparatus is driven as described above, thelubricant-containing polymer member 51 is also moved while it iscontacted or not contacted with the guide rail 1. Therefore, lubricantgradually oozes from the lubricant-containing polymer member 51. Sincethe lubricant-containing polymer member 51 is arranged close to the lipportion of the side seal 50 (the inner surface of the side seal 50 whichcomes into contact with the guide rail 1), the lip portion of the sideseal 50 is stably lubricated by this oozing lubricant over a long periodof time. In an arrangement in which the lubricant-containing polymermember 51 comes into contact with the guide rail 1, lubricant can be fedto the lip portion of the side seal 50 via the surface of the guide rail1. Accordingly, lubricant can be more stably fed to the lip portion inthis arrangement.

Due to the foregoing, the abrasion of the lip portion of the side seal50 can be minimized. Therefore, the sealing property of the side seal 50can be maintained over a long period of time, and the entrance of dirtand dust into the main body 2A can be prevented. As a result, the lifeof the linear guide apparatus can be prolonged.

Further, the lubricant that has oozed from the lubricant-containingpolymer member 51 is automatically fed to the rolling elements B, whichare rolling in the rolling grooves 3, 13, via the rolling grooves 3, 13.Due to the self-lubricity described above, it is possible for theapparatus to be smoothly operated over a long period of time.Accordingly, even if lubricant is not fed to the slider 2 from theoutside of the apparatus, operation can be smoothly continued over along period of time under the condition of low resisting torque.

In an arrangement in which the lubricant-containing polymer member 51comes into contact with the guide rail 1, as the lubricant oozes fromthe lubricant-containing polymer member 51, the lubricant-containingpolymer member 51 shrinks by itself. By the shrinking force, thelubricant-containing polymer member 51 closely comes into contact withthe surface of the guide rail 1 to be sealed. Therefore, thelubricant-containing polymer member 51 performs both the sealingfunction and the lubricating function.

When the side seal 50 is made of polyurethane rubber that has been curedunder the condition it contains grease, lubricant is fed by the sideseal 50 itself. Therefore, the abrasion of the lip portion of the sideseal 50 can be more reduced by the lubricant fed by the side seal 50itself.

Since the lubricant-containing polymer member 51 is interposed betweenthe end cap 2B and the side seal 50 via the reinforcing plate 52, thelip portion of the sealing 50 seldom gets rolled up during thereciprocating motion of the slider 2. Accordingly, it is possible toprevent the leakage of grease from the slider 2.

When the arrangement of the first embodiment is adopted, the greasenipple attaching hole may be closed with a blank plug. However, whennecessary, this hole may be opened at an appropriate time, so thatlubricant such as grease can be fed into the slider.

In the linear guide apparatus of the first embodiment, thelubricant-containing polymer member 51 is fixed to the end face of theend cap 2B under the condition that the lubricant-containing polymermember 51 is interposed between the reinforcing plate 52 and the sideseal 50. However, it should be noted that the present invention is notlimited to the first embodiment. For example, in the same manner as thatshown in FIG. 37, the side seal 50 is directly attached to the end faceof the end cap 2B, and the lubricant-containing polymer member 51 may befixed to the end face of the end cap 2B, to which the side seal 50 isattached, under the condition that the lubricant-containing polymermember 51 is interposed between two pieces of reinforcing plates 52.Even in the above arrangement, as long as the lubricant-containingpolymer member 51 is arranged close to the lip portion of the side seal50, the same effect as that of the first embodiment can be provided.

The present inventors made an experiment to check the abrasion of theside seal of the linear guide apparatus of the first embodiment. Theresult of the experiment will be explained below, referring to thecomparative example.

First, the linear guide apparatus of the first embodiment of the presentinvention, the arrangements of which are described in Examples (1), (2)and (3), were manufactured. As a comparative example, the linear guideapparatus, the arrangement of which is described in Example (4), wasmanufactured.

EXAMPLE 1

The side seal 50 was made of NBR rubber. The lubricant-containingpolymer member 51 was manufactured as follows. That is, 70% by weight ofparaffin mineral oil (FBK RO100 manufactured by Nippon Sekiyu Co.) to beused as lubricant was contained in polyethylene composed of 21% byweight of low molecular weight polyethylene (PZ50U manufactured byMitsubishi Yuka Co.) and 9% by weight of super high molecular weightpolyethylene (MIPELON XM220 manufactured by Mitsui Sekiyu Kagaku Co.).The thus obtained material was subjected to an injection molding machineand plasticized (melted). Then the plasticized material was injectedinto a predetermined metallic mold and cooled and solidified while itwas being pressured. There was provided a gap of 0 to 0.1 mm between theinner face of the lubricant-containing polymer member 51 and the surfaceof the guide rail 1. A portion of the inner face of thelubricant-containing polymer member 51, the area of which was about 70%of the inner face, was contacted with the surface of the guide rail 1.

EXAMPLE 2

An arrangement of Example (2) is the same as that of Example (1) exceptthat the side seal 40 was made of grease-containing polyurethane rubber.

The grease-containing polyurethane rubber was manufactured as follows.Mixture (CORONATE T-6 manufactured by Nippon Polyurethane Kogyo Co.) tobe used as polyisocyanate in which 2, 4-tolylenediisocyanate and 2,6-tolylenediisocyanate were mixed by a mixing ratio 65:35, was reactedwith polyesterpolyol (NIPPOLLAN 4032 manufactured by Nippon PolyurethaneKogyo Co.) to be used as active hydrogen compound, so that compound wasformed as a result of reaction. Polyisocyanate, active hydrogen compoundand grease were mixed with each other so that the thus formed compoundcould be mixed with mineral oil lithium soap grease (Alvania Grease No.2manufactured by Showa Shell Sekiyu K.K.) to be used as grease, by amixing ratio of 1:1. The thus obtained mixture was heated in anappropriate metallic mold and cured so that it was integrated into onebody.

EXAMPLE 3

The same side seal 50 and lubricant-containing polymer member 51 asthose of Example (1) were used. However, the lubricant-containingpolymer member 51 was not contacted with the guide rail 1, wherein a gap0.2 mm to 0.3 mm was formed between the inner face of thelubricant-containing polymer member 51 and the outer surface of theguide rail 1. In this connection, concerning a linear guide apparatus inwhich the side seal 50 was directly attached to the end face of the endcap 2B and in which the lubricant-containing polymer member 51interposed between two reinforcing plates 52 was fixed to the end faceof the cap 2B to which the side seal 50 was attached, the followingmeasurement was conducted under the same condition as that of Example(3). As a result of the measurement, the same result was obtained.

EXAMPLE 4

The side seal 50 was made of NBR rubber, and the lubricant-containingpolymer member 51 was not used.

The apparatus described in Examples (1) to (4) were operated in such amanner that the respective linear guide apparatus were made to run by5000 km, and then quantities of abrasion were measured. By themeasurement, the results shown on Table 1 were obtained. In thisconnection, although the side seals 50 were attached to both endportions of each linear guide apparatus, a quantity of abrasion of oneside seal 50 was measured.

TABLE 1 Quantity of Abrasion Linear Guide Apparatus (g/piece) Example(1) 0.007 Example (2) 0.002 Example (3) 0.01 Comparative Example (4)0.20

As can be seen in the result of the experiment, according to Examples(1), (2) and (3) of the present invention, a quantity of abrasion of theside seal 50 can be remarkably reduced, and the sealing property can bemaintained over a long period of time.

Further, the present inventors made another experiment to check anendurance of the linear guide apparatus operating in an environment ofbeing filled with wood cutting chips. In the endurance experiment, thelinear guide apparatus of the first embodiment is filled up with AlvaniaGrease No.2 mentioned above. The endurance experiment was carried out inthe environment of the wood cutting chips piled up so that the linearguide apparatus was entirely covered with the wood cutting chips. Theresult of the endurance experiment will be explained below, referring tothe comparative example.

TABLE 2 Composition of Relative lubricant-containing Linear Runningpolymer member Guide Apparatus Life (% by weight) Seal Comparative 1.0none NBR rubber Example (4) Example (1) 2.5 LPE: 21, HPE: 9, LUB: 70 NBRrubber Example (A) 2.3 LPE: 41, HPE: 9, LUB: 50 NBR rubber Example (B)1.7 LPE: 61, HPE: 9, LUB: 30 NBR rubber Comparative 1.1 LPE: 81, HPE: 9,LUB: 10 NBR rubber Example (C) Comparative 0.9 LPE: 21, HPE: 9, LUB: 70none Example (D)

In Table 2, Example (1) and Comparative Example (4) are the same asexamples shown in Table 1. Examples (A) and (B) as well as ComparativeExamples (C) and (D) were added for the endurance experiment. Therelative running life was represented by a ratio that the running lifeof Comparative Example (4) was taken as 1.0. Comparative Example and (D)used a reinforcing plate with no seal. In the column of Table 2regarding the composition of the lubricant-containing polymer member,“LPE” indicates low molecular weight polyethylene (PZ50U manufactured byMitsubishi Yuka Co.); “HPE” indicates super high muolecular weightpolyethylene (MIPELON XM220 manufactured by Mitsui Sekiyu Kagaku Co.);and “LUB” indicates paraffin mineral oil (FBK RO100 manufactured byNippon Sekiyu Co.) to be used as lubricant.

As can be seen in the result of the endurance experiment, when aquantity of lubricant is 50 to 80% by weight, the running life extendsremarkably. In contrast, when a quantity of lubricant is less than 30%by weight, the effect of extending the running life is small.Particularly, when a quantity of lubricant is 10% by weight less than20% by weight, the effect of extending the running life is not almostdeveloped.

Further, if the NBR rubber is not attached in the outside of thelubricant-containing polymer member, the lubricant-containing polymermember has a manufacturing limit of about 0 to 0.1 mm as a gap relativeto the guide rail. Accordingly, since the sealing property isdeteriorated, the wood cutting chips are prone to enter to the interiorof the linear guide apparatus, even compared with an example of only arubber seal attached to the end cap. Therefore, the running life of thelinear guide apparatus with no NBR rubber is made short.

Second Embodiment

Next, the second embodiment of the present invention is shown in FIGS. 1to 8B. A shape of the side seal of the apparatus of the secondembodiment is different from the shape of the side seal of the apparatusof the first embodiment, which is a main different point. The side seal12 of the second embodiment includes: a C-shaped steel plate, the shapeof which is the same as the shape of the end cap 2B; and a piece ofgrease-containing polyurethane rubber, the shape of which is similar tothe shape of the C-shaped steel plate, wherein the piece ofgrease-containing polyurethane rubber is integrally attached to an outersurface of the C-shaped steel plate.

There is provided a lip portion 13 of the side seal 12 which comes intocontact with the guide rail 1. An inside face of the lip portion 13 ofthe side seal 12 coming into contact g with the guide rail 1 is formedinto a shape so that the side seal 12 can slidably come into contactwith an upper face 1 a and an outer side face 1 b of the guide rail 1and so that a gap between the slider 2 and the guide rail 1 can besealed. More specifically, the lip portion 13 of the side seal 12 isformed into a shape so that the lip portion 13 can be slidably contactedwith the rolling element rolling grooves 3A, 3B and the run-off groove 3a. In this connection, in both wing portions 12A, 12B of the side seal12, there are formed through-holes 12 a, 12 b through which attachingscrews penetrate. In a connecting portion 12C that connects both wingportions 12A and 12B, there is formed a through-hole 12 c through whicha grease nipple is attached.

There is provided a lubricant-containing member 11 which is interposedbetween the side seal 12 and the reinforcing plate 10. Thislubricant-containing member 11 is formed into a substantial C-shape inaccordance with the outer shape of the end cap 2B. The inside face ofthe C-shaped lubricant-containing member 11 is not tapered but flat.Accordingly, in the same manner as that of the inner face of the lipportion 13, the inside face of the C-shaped lubricant-containing member11 can be contacted with an upper face 1 a of the guide rail 1 and anouter side face 1 b including the rolling element rolling grooves 3A, 3Bin accordance with the sectional shape of the guide rail 1.

As shown in FIG. 3A which is a front view and FIG. 3B which is a sideview of the lubricant-containing member 11, in both wing portions 11Aand 11B of the lubricant-containing member 11, there are formedthrough-holes 11 a, 11 b through which the attaching screws penetrate.In a connecting portion 11C to connect both wing portions 11A and 11B,there is formed a through-hole 11 c through which the grease nipple isattached. The through-holes 11 a, 11 b are respectively open to theoutside of the wing portions 11A, 11B. The through-hole 11 c is open tothe upper face side of the connecting portion 11C.

Dimensions of the recessed portion of this lubricant-containing member11 are determined so that the inner face of the recessed portion can beslidably contacted with the upper face 1 a of the guide rail 1 and theoutside face 1 b including the rolling element rolling grooves 3A, 3B.In portions on the inner face of the recessed portion of thelubricant-containing member 11 opposed to the rolling element rollinggrooves 3A, 3B and the run-off groove 3 a of the guide rail 1, there areprovided protrusions 11 f, 11 g, 11 d and 11 e which are formed so thatthey can slide on the inner faces of the grooves 3A, 3B and 3 a.Further, The shape of an inner bottom face 11 h of thelubricant-containing member 11, which slidably comes into contact withthe upper face 1 a of the guide rail 1, is formed into an arc, theradius of curvature of which is R, so that the center of the innerbottom face protrudes from both end portions close to the wing portions11A, 11B when the lubricant-containing member 11 is not given a forcefrom the outside.

Ring-shaped members 15A, 15B are inserted into the respectivethrough-holes 11 a, 11 b formed in both wing portions 11A, 11B of thelubricant-containing member 11. As shown in FIG. 4A which is a frontview of the ring-shaped members 15A, 15B and also as shown in FIG. 4Bwhich is a side view, the ring-shaped members 15A, 15B are shortcylindrical members, and the outer diameters of the ring-shaped members15A, 15B are appropriate to insert them into the through-holes 11 a, 11b easily.

A ring-shaped member (or a solid cylindrical member) 16 is inserted intothe through-hole 11 c formed in the connecting section 11C of thelubricant-containing member 11. As shown in FIG. 5A which is a frontview of the ring-shaped member 16 and also shown in FIG. 5B which is aside view, this ring-shaped member 16 is a short cylindrical member.However, the outer diameter D_(AR) of the ring-shaped member 16 islarger than the inner diameter D_(A) of the through-hole 11 c. That is,when the ring-shaped member 16 is inserted into the through-hole 11 c,the through-hole 11 c is expanded.

Further, the length V of the ring-shaped members 15A, 15B is a littlelonger than the thickness W of the lubricant-containing member 11, forexample, the length V of the ring-shaped members 15A, 15B is longer thanthe thickness W of the lubricant-containing member 11 by about 0.2 mm.That is, when the ring-shaped members 15A, 15B and 16 are respectivelyinserted into the through-holes 11 a to 11 c, as shown in FIG. 6, endportions of the ring-shaped members 15A, 15B and 16 protrude from thefront side or the reverse side of the lubricant-containing member 11.

The reinforcing plate 10, the lubricant-containing member 11 and theside seal 12 are integrally fixed to the main body 2A together with theend cap 2B when the attaching screws 17A, 17B, which penetrate thethrough-holes 2 a, 2 b of the end cap 2B and screw to the main body 2A,penetrate the through-holes 12 a, 12 b of the side seal 12, thering-shaped members 15A, 15B inside the through-holes 11 a, 11 b of thelubricant-containing member 11, and the through-holes 10 a, 10 b of thereinforcing plate 10.

Next, the mode of operation of the second embodiment will be explainedbelow.

When the linear guide apparatus is driven, the lubricant-containingmember 11 is moved coming into contact with the guide rail 1, andfrictional heat is generated. Being influenced by the frictional heat,lubricant gradually oozes from the lubricant-containing member 11. Afterthe lubricant has oozed out, it is automatically fed to the rollingelements, which are rolling in the rolling element rolling grooves 3A,3B, via the rolling element rolling grooves 3A, 3B. Due to theself-lubricity described above, it is possible for the apparatus to besmoothly operated over a long period of time. Accordingly, even iflubricant is not fed to the slider 2 from the outside of the apparatus,operation can be smoothly to continued over a long period of time underthe condition of low resisting torque.

As described above, the shape of the inner face of the recessed portionof the lubricant-containing member 11 is matched with the transversecross-sectional shape of the guide rail 1. Therefore, as shown in FIG.7, the lubricant-containing member 11 can be closely contacted with theupper face 1 a and the side face 1 b of the guide rail 1. As thelubricant oozes from the lubricant-containing member 11, thelubricant-containing polymer member 11 shrinks by itself. By theshrinking force, the lubricant-containing polymer member 11 closelycomes into contact with the surface of the guide rail 1 to be sealed atall times. Therefore, the lubricant-containing member 11 performs boththe sealing function and the lubricating function.

In the second embodiment, since the side seal 12 is used as a platemember on the outside of the lubricant-containing member 11, the sealingproperty can be more enhanced.

Especially, in the second embodiment, since an upper face side of thethrough-hole 11 c formed in the connecting section 11C of thelubricant-containing member 11 is cut away, the upper face side of thethrough-hole 11 c is open. Accordingly, as shown in FIG. 8A, the wingportions 11A and 11B can be easily expanded in the transverse direction.Therefore, the lubricant-containing member 11 can be easily attached inthe assembling process even if it is arranged striding the guide rail 1.

Into the through-hole 11 c of the lubricant-containing member 11, thering-shaped member 16, the outer diameter of which is larger than theinner diameter of the through-hole 11 c, is inserted to be used as apushing means. Accordingly, when the lubricant-containing member 11strides the guide rail 1 as shown in FIG. 8B, the ring-shaped member 16expands the through-hole 11 c in the transverse direction. Therefore, apushing force to push the wing portions 11A, 11B against the guide rail1 is generated by this pushing means. Due to the foregoing, even if somemanufacturing errors are caused in the size of the lubricant-containingmember 11, or even if the lubricant-containing member 11 wears away alittle, it is possible to make the lubricant-containing member 11closely come into contact with the surface of the guide rail 1 to besealed at all times. In this case, due to the structure of thethrough-hole 11 c, the upper face side of which is open, a force toexpand the through-hole 11 c by the ring-shaped member 16 is effectivelyconverted into a pushing force to push the wing portions 11A, 11Bagainst the guide rail 1. Therefore, this structure of the through-hole11 c is very advantageous.

The length V of the ring-shaped members 15A, 15B is a little longer thanthe thickness W of the lubricant-containing member 11. Therefore, endportions of the ring-shaped members 15A, 15 b and 16 are protruded fromthe front side or the reverse side of the lubricant-containing member11. Since the attaching means for attaching the lubricant-containingmember 11 is composed in the above manner, although thelubricant-containing member 11 is interposed between the reinforcingplate 10 and the side seal 12, the friction can be reduced. Due to theforegoing arrangement, the lubricant-containing member 11 is smoothlydeformed by the self-shrinkage and the aforementioned pushing force in adirection perpendicular to the axial direction of the guide rail 1.Accordingly, it is possible to make the lubricant-containing member 11closely come into contact with the guide rail 1 at all times.

As described above, the inner bottom surface 11 h of the recessedportion of the lubricant-containing member 11 is formed into an arc.Therefore, when the wing portions 11A, 11B of the lubricant-containingmember 11 are deformed being pushed against the guide rail 1 by theself-shrinkage or the pushing force, the inner bottom surface 11 h isput into a substantially horizontal condition, and the inner bottomsurface 11 h stably comes into contact with the upper face 1 a of theguide rail 1.

Since the lubricant-containing member 11 is interposed between thereinforcing plate 10 and the side seal 12, it is easy to increase thesize of the lubricant-containing member 11 so that a sufficient quantityof lubricant can be contained in the member to continue a smooth rollingmotion of the rolling elements over a long period of time. Further,since the lubricant-containing member 11 is not made to adhere onto asteel plate or other members, it is possible to reduce the cost of thelubricant-containing member 11 which is an article of consumption.Furthermore, it is possible to save time and labor when thelubricant-containing member 11 is replaced.

Since the lubricant-containing member 11 is interposed between thereinforcing plate 10 and the side seal 12, it is difficult for the lipportion 13, which is a portion of the side seal 12 to be contacted withthe guide rail 1, to get rolled up when the slider 2 is reciprocated.Accordingly, the leakage of grease from the slider 2 can be reduced.

After the lubricant has oozed from the lubricant-containing member 11,it is fed to the lip portion 13 of the side seal 12 which comes intocontact with the guide rail 1. Therefore, the lubricant that has oozedfrom the lubricant-containing member 11 is useful for the reduction ofabrasion of the lip portion 13. Especially, in the second embodiment,the lip portion 13 is made of polyurethane rubber that has been curedunder the condition that grease is contained in it. Accordingly, thelubricant is fed by the lip portion 13 itself, and the abrasion of thelip portion 13 can be more reduced.

Since the abrasion of the lip portion 13 can be minimized, the sealingproperty of the lip portion 13 can be maintained over a long period oftime, and further it is possible to prevent the intrusion of foreignobjects into the main body 2A.

Accordingly, the life of the linear guide apparatus can be prolonged.

According to the arrangement of the second embodiment, lubricant is fedfrom the lubricant-containing member 11 to the rolling elements at alltimes. Therefore, the grease nipple attaching hole may be closed with ablank plug, however, this grease nipple attaching hole may be openedwhen necessary so as to feed lubricant into the slider.

In the second embodiment, the side seal 12 corresponds to the platemember, the reinforcing plate 10 corresponds to another plate member,and the ring-shaped member 16 corresponds to the pushing means.

Third Embodiment

FIGS. 9 and 10 are views showing the third embodiment of the presentinvention. In this connection, like reference characters are used toindicate like parts in the views showing the second embodiment and thethird one, and the overlapping explanations are omitted here.

The arrangement of the linear guide apparatus of the third embodiment isthe same as that of the first embodiment described above, except thatthe shape of the lubricant-containing member 11 is changed.

Specifically, as shown in FIG. 9 which is a front view of thelubricant-containing member 11, the shape of the lubricant-containingmember 11 is composed as follows. In the wing portions 11A, 11B, thereare formed cutout portions 20A, 20B which continue to the through-holes11 a, 11 b through which the attaching screws penetrate, and the outsideand the front end side of the wing portions 11A, 11B are opened by thecutout portions 20A, 20B, and the inner diameters of the ring-shapedmembers 15A, 15B, which are inserted into the through-holes 11 a, 11 b,are made to be larger than the outer diameters of the attaching screws17A, 17B. Other arrangements are the same as those of the secondembodiment.

According to the above arrangement, as shown in FIG. 10 which is a frontview of the lubricant-containing member 11 arranged in a condition ofstriding the guide rail 1, when the attaching screws 17A, 17B areloosened, the ring-shaped members 15A, 15B can be moved outside.Therefore, only the lubricant-containing member 11 can be removed fromthe linear guide apparatus being pulled upward. In this way, thelubricant-containing member 11 can be removed from the linear guideapparatus. A new lubricant-containing member 11 can be inserted into thelinear guide apparatus from the upside without removing the side sealsand others from the main body 2A. The lubricant-containing member 11 canbe incorporated to the main body in such a manner that the ring-shapedmembers 15A, 15B are pushed into the through-holes 11 a, 11 b, and thenthe attaching screws 17A, 17B are fastened.

According to the arrangement of the third embodiment of the presentinvention, the lubricant-containing member 11 from which the lubricanthas completely oozed can be easily replaced with a newlubricant-containing member 11, which is called a cassette system.Therefore, it is possible to feed the lubricant without requiring muchtime and labor while the operator's hands are maintained clean.

Other point of the third embodiment are the same as those of the firstembodiment described before.

Fourth Embodiment

FIGS. 11 to 17 are views showing the fourth embodiment of the presentinvention. In this connection, like reference characters are used toindicate like parts in the views showing the first to third embodimentsdescribed before, and the overlapping explanations are omitted here.

In the fourth embodiment, an arrangement to generate a pushing force topush the wing portions 11A, 11B of the lubricant-containing member 11against the guide rail 1 is different from that of the first and secondembodiments described before.

The specific arrangement is shown in FIGS. 11, 12A and 12B. FIG. 11 is aperspective view showing an assembling condition of the end portion ofthe slider 2, FIG. 12A is a front view of the lubricant-containingmember 11, and FIG. 12B is a side view of the lubricant-containingmember 11. As shown in these drawings, the lubricant-containing member11 is composed as follows. The through-hole 11 c of thelubricant-containing member 11 is omitted. On the surface of thelubricant-containing member 11 on the front side of the side seal 12,there is formed a continuous C-shaped groove 30 which surrounds therecessed portion of the lubricant-containing member 11. In the groove30, there is provided an elastic body 31 which acts as the pushing meansshown in FIG. 13A which is a front view, and FIG. 13B which is a bottomview.

The elastic body 31 is an elastically deformable member made of steel,synthetic resin or hard rubber. The shape of the elastic body 31 is asubstantial C-shape in accordance with the shape of the groove 30. Underthe condition that the elastic body 31 is not given a force from theoutside, the width of the opening side of the C-shape is a littlereduced.

Other points of the fourth embodiment are the same as those of the firstand second embodiments described before. However, according to thefourth embodiment, the through-hole 11 c of the lubricant-containingmember 11 is omitted, and the through-hole 10 c of the reinforcing plate10 and the through-hole 12 c of the side seal 12 are also omitted, sothat the grease nipple is not provided. However, like the secondembodiment described before, the through-holes 10 c, 11 c, 12 c may beformed, and the grease nipple attaching hole is closed with a blank plugin a normal operating condition and opened when necessary so as to feedlubricant such as grease into the slider.

According to the arrangement of the fourth embodiment, as shown in FIG.14, a pushing force to push the wing portions 11A, 11B of thelubricant-containing member 11 against the guide rail 1 is generated byan elastic force of the elastic body 31 provided in the groove 30, andas shown in FIG. 15, when the lubricant-containing member 11 is attachedto the apparatus, the wing portions 11A, 11B can be expanded in thetransverse direction. Accordingly, as shown in FIG. 16, it is possibleto make the lubricant-containing member 11 closely come into contactwith the guide rail 1 in a stable condition. Since the shape of theelastic body 31 is determined in such a manner that an interval of thefront end portions is reduced when no load is given, even if thelubricant-containing member 11 wears away a little, the inner surfacesof the wing portions 11A, 11B can be more positively pressed against theguide rail 1. As shown in FIG. 17, since the ring-shaped members 15A,15B protrude from the surface of the lubricant-containing member 11 inthe same manner as that of the first embodiment described before, thelubricant-containing member 11 can be smoothly deformed.

In the above explanations, it can be seen that the same effect as thatof the first and second embodiments is provided by the fourthembodiment.

Since the elastic body 31 to generate a pushing force is arranged insuch a manner that it surrounds the recess of the lubricant-containingmember 11 and the end portions of the elastic body 31 are extended topositions close to the front end portions of the wing portions 11A, 11B,the pushing force generated by the elastic body can be more positivelytransmitted to the wing portions 11A, 11B.

Fifth Embodiment

FIGS. 18A and 18B are views showing the fifth embodiment of the presentinvention. FIG. 18A is a front view of the lubricant-containing member11. FIG. 18B is a cross-sectional view taken on line XVIII—XVIII in FIG.18A.

An arrangement of the fifth embodiment is essentially the same as thatof the fourth embodiment described above. A different point is that asubstantially rectangular cutout portion 11D, which is open upward, isformed on an upper surface of the connecting section 11C of thelubricant-containing member 11.

When the above cutout portion 11D is formed, the rigidity of theconnecting section 11C is lowered. Therefore, an elastic force generatedby the elastic body 31 is effectively converted into a pushing force bywhich the wing portions 11A, 11B can be pressed against the guide rail1. Accordingly, it becomes possible to make the lubricant-containingmember 11 more positively come into contact with the guide rail 1. Otherpoints are the same as those of the fourth embodiment described before.

Sixth Embodiment

FIGS. 19A to 22 are views showing the sixth embodiment of the presentinvention. In this connection, like reference characters are used toindicate like parts, and the overlapping explanations are omitted here.

In the sixth embodiment, as shown in FIG. 19A which is a front view ofthe lubricant-containing member 11 and FIG. 19B which is a side view,there is formed a continuous outer circumferential groove 33 on theouter surfaces of the wing portions 11A, 11B and also on the uppersurface of the connecting section 11C. In this connection, at both endsof the outer circumferential groove 33, there are formed recesses 33 awhich enter the inside of both wing portions 11A, 11B.

An elastic body 34 shown in FIG. 20, which acts as the pushing means, isengaged with the outer circumferential groove 33. An arrangement of theelastic body 34 is the same as that of the elastic body 31 shown in thefourth embodiment, except that the size of the elastic body 34 isincreased and protrusions 34 a to be engaged with the recesses 33 a areformed at the front end portions.

In the above arrangement, as shown in FIG. 21A, the elastic body 34pushes the wing portions 11A, 11B to the guide rail 1. Therefore, thelubricant-containing member 11 can be made to stably come into closecontact with the guide rail 1. Since the ring-shaped members 15A, 15Bprotrude from the surface of the lubricant-containing member 11 as shownin FIG. 21B in the same manner as that of the above second embodiment,the lubricant-containing member 11 can be smoothly deformed.Accordingly, the same effect as that of the fourth embodiment can beprovided by the sixth embodiment.

According to the arrangement of the sealing device 8 of the sixthembodiment as shown in FIG. 22, only the elastic body 34 can be removedwithout loosening or removing the attaching screws 17A, 17B. For thisreason, it is possible to attach the elastic body 34 after all the partshave been attached. Therefore, this arrangement can be variously used.For example, when it is unnecessary to press the lubricant-containingmember 11 against the guide rail 1, the elastic body 34 is removed, andonly when it becomes necessary to press the lubricant-containing member11 against the guide rail 1, the elastic body 34 is attached.Alternatively, when it is required that an intensity of the pushingforce of the lubricant-containing member 11 against the guide rail 1 ischanged, the elastic body 34 is replaced with another one.

For example, this arrangement can be used as follows. Immediately afterthe use of a new lubricant-containing member 11 is started, thelubricant-containing member 11 seldom wears away, so that thelubricant-containing member 11 can be made to closely come into contactwith the guide rail 1. In this case, when the elastic body 34 isattached to the lubricant-containing member 11, too much lubricant oozesfrom the lubricant-containing member 11. Therefore, the elastic body 34is previously removed. When the lubricant-containing member 11 wearsaway and it becomes difficult to make the lubricant-containing member 11closely come into contact with the guide rail 1, the elastic body 34 isattached so as to make the lubricant-containing member 11 closely comeinto contact with the guide rail 1. In the event of progress ofabrasion, the elastic body 34 is replaced with a more elastic body. Inthis way, a quantity of oozing lubricant can be stably maintained at anappropriate value at all times.

In the sixth embodiment, there are formed recesses 33 a at both ends ofthe outer circumferential groove 33, and also there are formedprotrusions 34 a engaging with these recesses 33 a at both ends of theelastic body 34. Accordingly, even if the elastic body 34 is set fromthe outside, there is no possibility that the elastic body 34 easilyfalls off or slips in a direction in which the elastic body 34 isdisconnected from the apparatus.

Seventh Embodiment

FIG. 23 is a view showing the seventh embodiment of the presentinvention. FIG. 23 is a front view of the lubricant-containing member11.

An arrangement of the seventh embodiment is essentially the same as thatof the fourth embodiment described before. A different point is that asubstantially rectangular cutout portion 11D, which is open upward, isformed on an upper surface of the connecting section 11C of thelubricant-containing member 11. Due to the foregoing, the same effect asthat of the fifth embodiment can be provided by this embodiment, andother effects are the same as those of the sixth embodiment.

Eighth Embodiment

FIGS. 24 to 26B are views showing the eighth embodiment of the presentinvention. In this connection, like reference characters are used toindicate like parts in the views showing each embodiment describedbefore, and the overlapping is; explanations are omitted here.

In the eighth embodiment, as shown in FIG. 24 which is a front view ofthe lubricant-containing member 11, in the connecting section 11 c ofthe lubricant-containing member 11, there is formed a linear groove 37extending in the width direction of the lubricant-containing member 11.Into this groove 37, an elastic body 38 is set which acts as the pushingmeans shown in FIG. 25A which is a front view and FIG. 25B which is abottom view.

The elastic body 38 is a thin prism-shaped elastic member made of steel,synthetic resin or hard rubber, which is a little curved. As shown inFIG. 26A which is a front view and FIG. 26B which is a side view, theelastic body 38 is set into the groove 37 while the elastic body 38 iscurved in a direction reverse to its curved shape.

Even in this arrangement, the connecting section 11C of thelubricant-containing member 11 is curved inside by an elastic restoringforce of the elastic body 38. Therefore, a pushing force to push thewing portions 11A, 11B against the guide rail 1 is generated.Accordingly, the same effect as that of the second embodiment describedbefore can be provided by the eighth embodiment.

Ninth Embodiment

FIGS. 27 to 29B are views showing the ninth embodiment of the presentinvention. In this connection, like reference characters are used toindicate like parts in the views showing the embodiments describedbefore, and the overlapping explanations are omitted here.

In the ninth embodiment, as shown in FIG. 27 which is a front view ofthe lubricant-containing member 11, in the connecting section 11 c ofthe lubricant-containing member 11, there is formed a rectangularthrough-hole 39 which is long in the transverse direction. In thisconnection, on the upper side of the lubricant-containing member 11,there is formed a cutout portion 11E through which the through-hole 39communicates with the outside.

As shown in FIG. 28A which is a front view and FIG. 28B which is a sideview, a coil spring 40, which acts as the pushing means, is accommodatedin the through-hole 39 under the condition that its expanding directionis aligned in the transverse direction and it is compressed as shown inFIG. 29A which is a front view and FIG. 29B which is a partially cutawayside view.

According to this arrangement, the rigidity of the connecting section11C in the transverse direction is reduced by the action of the cutout11E, and the connecting section 11C of the lubricant-containing member11 is expanded in the transverse direction by an elastic restoring forceof the coil spring 40. As a result, a pushing force to push the wingportions 11A, 11B to the guide rail 1 is generated. Therefore, the sameeffect as that of the second embodiment described before can be providedby the ninth embodiment.

Tenth Embodiment

FIGS. 30A to 30B are views showing the tenth embodiment of the presentinvention. FIG. 30A is a front view, and FIG. 30B is a partially cutawayside view. In this connection, like reference characters are used toindicate like parts in the views showing the embodiments describedbefore, and the overlapping explanations are omitted here.

The tenth embodiment is arranged as follows. In the wing portions 11A,11B of the lubricant-containing member 11, there are formed slits 41A,41B extending in the upward and downward direction, and ends of theslits 41A, 41B are open to the front end sides of the wing portions 11A,11B. In the intermediate portions of these slits 41A, 41B, there areformed rectangular through-holes 42A, 42B which are long in thetransverse direction. In the through-holes 42A, 42B, there are providedcoil springs 43A, 43B, which act as pushing means, the expandingdirection of which is aligned in the transverse direction, wherein thecoil springs 43A, 43B are set in the through-holes 42A, 42B being alittle compressed.

According to the above arrangement, the rigidity of the connectingsection 11C in the transverse direction is reduced by the action of theslits 41A, 41B, and elastic restoring forces of the coil springs 43A,43B are used as pushing forces to press the wing portions 11A, 11 bagainst the guide rail 1. Accordingly, the same effect as that of thesecond embodiment can be provided by the tenth embodiment.

Eleventh Embodiment

FIGS. 31A to 31D are views showing the eleventh embodiment of thepresent invention. FIGS. 31A to 31D are perspective views showingvariations of the ring-shaped member 16 to be set in the through-hole 11c of the lubricant-containing member 11. In this connection, thearrangement of the eleventh embodiment is the same as that of the secondembodiment except for the structure of the ring-shaped member 16.

In the eleventh embodiment, the ring-shaped member 16, which acts as thepushing means, is made of deformable material such as metal or highpolymer (plastics and rubber). On the outer circumferential surface ofthe ring-shaped member 16, there are formed slits 16 a extending in theaxial direction.

In the same manner as that of each embodiment described before, theinner diameter of the through-hole 11 c is made to be a little smallerthan the outer diameter of the ring-shaped member 16, so that thering-shaped member 16 can be inserted into the through-hole 11 c underthe condition that the diameter of the ring-shaped member 16 is a littlereduced. Since the slits 16 a are formed in the eleventh embodiment, thering-shaped member 16 can be more smoothly, elastically deformed in thedirection in which the diameter of the ring-shaped member 16 is reduced.Due to the foregoing, an expanding action by which the through-hole 11 cis expanded can be stably provided by the ring-shaped member 16 over along period of time. Accordingly, the wing portions 11A, 11B can bestably pressed against the guide rail 1 over a long period of time, andthe same effect as that of the second embodiment can be more positivelyprovided.

In this connection, the diameter expanding action of the ring-shapedmember 16 engaged with the through-hole 11 c is determined by the sizeand number of the slits 16 a formed in the ring-shaped member 16 andalso determined by the wall thickness and material of the ring-shapedmember 16. A pushing force to push the wing portions 11A, 11B againstthe guide rail 1 and a permissible abrasion loss of thelubricant-containing member 11 are determined by the deformationcharacteristic of the ring-shaped member 16. Accordingly, it isnecessary to appropriately determine the above factors by the size andspecification of the linear guide apparatus to be used and the rigidityof the lubricant-containing member 11. Consequently, the number of theslits 16 a is not limited to the specific embodiments shown in FIGS. 31Ato 31D, but it can be determined arbitrarily.

FIGS. 32A to 32C are views showing variations of the eleventhembodiment. In the variations, instead of the ring-shaped member 16, asolid columnar member 16A is used as a pushing means, which is engagedin the through-hole 11 c, wherein slits 16 b are formed in the columnarmember 16A so that the diameter can be expanded and contracted. Evenwhen this columnar member 16A is used, the same effect as that of thering-shaped members 16 shown in FIGS. 31A to 31D can be provided. Inthis connection, the diameter expanding action of this columnar member16 is determined by the material and the size and number of the slits 16b. Accordingly, in the same manner as that of the ring-shaped member 16,it is necessary to appropriately determine the above factors by the sizeand specification of the linear guide apparatus to be used and therigidity of the lubricant-containing member 11. Consequently, the numberof the slits 16 b is not limited to the specific embodiments shown inFIGS. 32A to 32C, but it can be determined arbitrarily.

Twelfth Embodiment

FIG. 33 is a view showing the twelfth embodiment of the presentinvention. FIG. 33 is a front view of the lubricant-containing member 11when it is arranged striding the guide rail 1. In this connection, likereference characters are used to indicate like parts in the viewsshowing the embodiments described before, and the overlappingexplanations are omitted here.

In the twelfth embodiment, there are formed two through-holes 11 c atpositions in the connecting sections 11C of the lubricant-containingmember 11 close to both wing portions 11A, 11B. The ring-shaped member16 having the slits 16 a shown in the eleventh embodiment is insertedinto each through-hole 11 c.

In the above arrangement in which a plurality of is through-holes 11 cand ring-shaped members 16 are provided, the connecting section 11C ofthe lubricant-containing member 11 is curved by a force to expand thediameter of each ring-shaped member 16. Therefore, a pushing force topush the wing portions 11A, 11B against the guide rail 1 is generated.Accordingly, the same effect as that of the second embodiment can beprovided. In this connection, the number of the through-holes 11 c maybe not less than 3, and instead of the ring-shaped member 16, thecolumnar members 16A shown in FIG. 32 may be inserted into a pluralityof through-holes 11 c.

In the twelfth embodiment, explanations are made for a case in which thelip portion 13 is formed from rubber containing lubricant. However,since lubricant is fed from the lubricant-containing member 11 to thelip portion 13, the lip portion 13 may be made of NBR (acrylonitrilebutadiene rubber) not containing lubricant.

In each embodiment described before, the reinforcing plate 10 may beomitted, and the lubricant-containing member 11 may be interposedbetween the end cap 2B and side seal 12. Since the lubricant-containingmember 11 substantially functions as a sealing device, instead of theside seal 12, a 40 steel plate like the reinforcing plate 10 may bearranged as a reinforcing plate or a protector. Under certaincircumstances, instead of the reinforcing plate 10, the side seal 12 maybe interposed between the lubricant-containing member 11 and the end cap2B.

In each embodiment described before, the length V of the ring-shapedmembers 15A, 15B, 16 is determined to be longer than the thickness W ofthe lubricant-containing member 11. However, the length V may be thesame as the thickness W, or the length V may be a little shorter thethickness W. The essential point to determine the length V and thethickness W is described as follows. A relation between the length V andthe thickness W must be maintained so that a deformation of thelubricant-containing member 11 in a direction perpendicular to the axialdirection of the guide rail 1 can not be obstructed when thelubricant-containing member 11 is fixed by fastening the attachingscrews 17A, 17B.

The linear guide apparatus to which the present invention is applied isnot limited to the apparatus of the embodiments described above. Forexample, the present invention can be applied to a linear guideapparatus in which two or more rolling element rolling grooves areformed on one side, or the rolling elements are not balls but rollers.

As explained above, according to the invention, lubricant can be verystably fed to the lip portion, so that the abrasion of the lip portioncan be minimized, and the sealing property of the sealing device can bemaintained at a high level over a long period of time. Therefore, theintrusion of foreign object into the linear guide apparatus can besuppressed and the life of the linear guide apparatus can be prolonged.

Further, the lubricant gradually oozing from the lubricant-containingmember can be fed to the rolling elements via the guide rail.Accordingly, the rolling elements can be smoothly rolled. In this case,when the side seal is used as a plate member, the abrasion of a contactsurface of the side seal with the guide rail can be reduced by theaction of lubricant fed from the lubricant-containing member. Therefore,the intrusion of foreign objects into the rolling element rolling groovecan be prevented, and the life of the linear guide apparatus can be moreprolonged.

Moreover, it is possible to make the lubricant-containing member comeinto contact with the guide rail at all times. Therefore, the lubricantthat has oozed from the lubricant-containing member can be stably fed tothe rolling elements via the guide rail. As a result, the rollingelements can be more smoothly rolled.

Still further, the lubricant-containing member can be made to stablycome into contact with the guide rail. Therefore, the lubricant can bemore stably fed to the rolling elements via the guide rail.

Thirteenth Embodiment

The thirteenth embodiment of the present invention is shown in FIGS. 39to 42.

The under seal 21 is composed of an under seal reinforcing plate 22 andan under seal body 23 made of lubricant-containing rubber or syntheticresin which adheres onto the under seal reinforcing plate 22. The underseal reinforcing plate 22 is made of a rectangular steel plate, thelength of which is substantially the same as that of the slider 2, andthe width of which is a little larger than the width of the lower endface 24 of the slider body 2A. An inner side edge of the under sealreinforcing plate 22 protrudes a little from an end of the lower endface 24 of the slider body 2A. The seal body 23 is made oflubricant-containing synthetic rubber or synthetic resin. The seal body23 is made to adhere onto the under seal reinforcing plate 22, which isa rectangular plate, by adhesion or baking while the seal body 23 is letto come near the inner edge side of the under seal reinforcing plate 22.At an end edge of the seal body 23, there is provided a seal lip L₁which comes into contact with the side 1 b of the guide rail 1. In thisway, the seal lip portion is composed. s As shown in FIG. 42, in aportion of the seal lip L₁ which comes into contact with the sidesurface 1 b of the guide rail 1, there are provided three cutoutportions 25 extending in the longitudinal direction of the seal body 23,wherein these cutout portions 25 are arranged in the thickness directionof the seal body 23. Due to the foregoing arrangement, the seal lip L₁is divided into four pieces.

As shown in FIG. 39, the side seal 61 is composed in such a manner thata lubricant-containing seal body 63 made of the same material as that ofthe seal body 23 is made to adhere by adhesion or baking onto an outersurface of the side seal reinforcing plate 62 made of a thin C-shapedsteel plate, the shape of which is substantially the same as that of theend cap 2B. In the C-shaped seal body 63, on both side surfaces opposedto each other, there are provided groove sliding protrusions 64 a, 64 bwhich are respectively engaged with ball rolling grooves 3 of the guiderail 1, the number of which is two with respect to one side of the-guiderail 1. The seal lip L₂ is formed on an inner edge of the seal body 63which comes into contact with the outer surface of the guide rail 1. Onthe surface of this side seal 61, there is formed one grease nippleattaching hole 66 in conjunction with a plurality of attaching holes 65through which the side seal 61 is attached to the end cap 2B.

In a portion of the seal lip L₂ which comes into contact with the ballrolling groove 3, that is, in a portion of the groove sliding protrusion64, as shown in FIGS. 40 and 41, there are formed three cutout portions66 in the thickness direction of the seal body 63. By the above cutoutportions 66, the seal lip L₂ is divided into 4 pieces.

Next, the action will be explained as follows.

The under seal 21 is attached as follows.

The slider 2 is previously assembled by attaching the end caps 2B toboth end portions of the slider body 2A. The under seal 21 is fixed insuch a manner that both end portions of the under seal 21 in thelongitudinal direction are engaged with attaching grooves 26 formed onthe lower surface of the front and rear end cap 2B while the front endof the seal lip L₁ is set inside. The seal body 23 composing the seallip portion of the under seal 21 allows the seal lip L₁, which protrudesinside a little from the side edge of the lower end face 24 of theslider body 2A, to come into contact with the side surface 1 b of theguide rail 1.

On the other hand, the side seals 61 are respectively attached onto bothend faces of the slider 2 when the screws 67 inserted into the attachingholes 65 are engaged with the screw holes (not shown) formed in the endcaps 2B. Concerning the seal body 63 composing the seal lip portion ofthe side seal 61, the seal lips L₂ protruding to the inner edgerespectively come into contact with the side surface 1 b of the guiderail 1, the groove surface of the ball rolling groove 3, and the uppersurface 1 a of the guide rail 1.

In this way, by the under seal 21, a lower opening of the gap betweenthe guide rail 1 and the slider 2 can be sealed. Further, by the sideseal 61, front and rear openings of the gap between the guide rail 1 andthe slider 2 can be sealed. Accordingly, the intrusion of dirt and dustfrom the front, the rear and the lower portion of the slider 2 can beperfectly blocked.

Further, the self-lubricity is provided to the sliding surfaces of theunder seal 21 and the side seal 61 by the lubricant-containing sealbodies 23, 63. Therefore, the sliding resistance of the contact seal isvery low, and the abrasion seldom occurs.

Even when this linear guide is used in an environment in which dirt anddust such as chips of wood and chips of casting are scattered, and evenwhen a portion of the lubricant is absorbed by the dirt and dust,lubricant is fed from the lubricant-containing seal bodies 23, 63 at alltimes. Accordingly, there is no possibility of defective lubrication.

Further, a plurality of cutout portions are formed in the contactportion of the seal lip L₁ which comes into contact with the side 1 b ofthe guide rail 1, and also a plurality of cutout portions are formed inthe contact portion of the seal lip L₂ which comes into contact with theupper face and the side of the guide rail 1. By these cutout portions,both seal lips L₁ and L₂ are respectively divided into 4 pieces.Therefore, either of the pieces of the divided seal lip L₁ (L₂) iscontacted with the outer surface of the guide rail 1, the shape of whichis complicated. In this way, the seal lip L₁ (L₂) can easily follow theshape of the guide rail 1. Even if the under rail 21 or the side rail 61is dislocated a little, the dislocation can be absorbed by thedeformation of the divided portions.

Moreover, the seal lips L₁ and L₂ are respectively divided into 4pieces. Therefore, the contact area of the seal lip of the thirtiethembodiment can be more increased than that of the seal lip of theconventional apparatus in which the seal lip is divided into 2 pieces.As a result, quantities of lubricant oozing from seal lips L₁ and L₂ canbe increased. Further, since the numbers of the seal lips L₁ and L₂ areincreased, the dust protecting function of the sealing device can bemore enhanced, and the lubricant in the sealing device is prevented fromdiffusing outside.

Since three cutout portions are formed in each of the seal lips L₁ andL₂, it is possible to increase the lubricant holding space compared withthe conventional apparatus in which one groove is formed in the seallip. As a result, the-sliding property of the seal lips L₁ and L₂ can beenhanced.

In this connection, each seal lip L₁, L₂ is provided with three cutoutportions and divided into four pieces. However, it should be noted thatthe present invention is not limited to the above specific embodiment.For example, each seal lip L₁, L₂ may be provided with two or not lessthan four cutout portions and divided into three or not less than fivepieces.

Only the under seal on one side is shown in FIG. 41. However, the underseals can be attached onto the lower end faces 24 on both sides of theslider body 2A. The under seal 21 is not necessarily attached by theengagement system, but the under seal 21 may be attached by rivets orscrews. The essential point is that the sealing device of the presentinvention is not influenced by the attaching structure of the under seal21.

Several variations of the side seal are shown in FIGS. 43 to 51.

The side seal shown in FIG. 43 is arranged as follows. In the samemanner as that of the thirtieth embodiment, three cutout portions 66 aare formed in the seal lip L₂, so that the seal lip L₂ is divided Autofour pieces, and both outside pieces of the divided seal lip L₂ are madeto be longer than other pieces. Due to the above arrangement, when thedivided seal lip L₂ are made to come into contact with the guide rail 1,both outside seal lips L₂ are greatly extended outside, so that thecontact area can be increased. As a result, a quantity of lubricantoozing from the seal lip can be more increased, and the lubricantholding capacity of the seal lip can be more enhanced.

The side seal shown in FIGS. 44 and 45 are arranged as follows.Checker-shaped cutout portions 66 b are formed in the seal lip L₂.Therefore, the seal lip L₂ is divided into a large number of pieces bythe checker-shaped cutout portions 66 b. Due to the foregoingarrangement, the number and the contact area of the pieces of thedivided seal lip L₂ can be more increased.

Cutout portions 66 formed in the side seals shown in FIGS. 46 to 49 arecomposed of not only simple straight lines but also curves. By thecombination of straight lines and curves, zigzag cutout portions areformed. The side seal shown in FIGS. 50 and 51 is arranged as follows.When the seal lip portions L₂ of the side seal comes into contact withthe guide rail 1, the cutout portion 66 is divided into two (a pluralnumber). This arrangement is effective when the rigidity of the lipportion L₂ is required by increasing the width of its central portion.

As long as the slider is attached to the guide rail in such a mannerthat the slider strides the guide rail, the linear guide apparatus ofthe present invention is not limited to the specific type. For example,in the embodiments described above, the number of the ball rollinggrooves 3 on one side is two, however, it is possible to apply thepresent invention to an apparatus, the number of the ball rollinggrooves on one side of which is one or not less than three. In thiscase, of course, it is possible to form the sliding protrusions 64 a, 64b of the side seal 61 in accordance with the ball rolling groove 3.

In the embodiments described above, balls are used as the rollingelements. However, it should be noted that the present invention can beapplied to an apparatus in which rollers are used as the rollingelements.

A direction of the cutout portions formed in the seal lips L₁, L₂ is notparticularly limited. For example, the cutout portions may be formed inan arbitrary direction such as a direction oblique with respect to theaxial direction of the guide rail.

In the embodiments described above, the cutout portions are formed onthe overall inner circumferential wall of the side seal. However, thepresent invention is not limited to the specific embodiment. Whennecessary, the cutout portions may be formed only in a portion of theball rolling groove 3 or on an upper surface of the guide rail 1. Inthis way, the cutout portions may be formed only in a portion of theside rail.

In the embodiments described above, the main purpose of the side seal isto accomplish the sealing function. However, it is possible to adopt thefollowing arrangement. In the slider, there is provided a conventionalside seal to which a piece of nitrile rubber or urethane rubber isattached by melting. Different from the above side seal, there isprovided in series a sealing device of the present invention. Thissealing device may be used as a lubricant feed device to feed lubricantto the seal lip portion and the rolling elements of the conventionalside seal.

There are formed a plurality of cutout portions in a portion of the seallip which comes into pressure contact with an outer surface of the guiderail. Accordingly, either of the divided portions of the seal lip comesinto contact with an outer surface of the guide rail, the shape of whichis complicated. Therefore, the seal lip easily follows the complicatedshape of the guide rail.

Further, there are provided a plurality of cutout portions in the seallip portion. Accordingly, compared with the conventional sealing devicein which one groove is formed in the seal lip portion, the contact areaof the seal lip which comes into contact with the guide rail can beincreased. As a result, it is possible to increase a quantity oflubricant oozing from the seal lip portion. Moreover, the number of thepieces of the divided seal lip can be increased more than the number ofthe pieces of the conventional seal lips. Accordingly, the dustprotecting function of the sealing device can be more enhanced, and thelubricant in the sealing device is prevented from diffusing outside.

Since a plurality of cutout portions are formed in the seal lip, it ispossible to increase the lubricant holding space compared with theconventional sealing device in which one groove is formed in the seallip. As a result, the sliding property of the seal lip can be enhanced.

What is claimed is:
 1. A linear guide apparatus comprising: an axiallyextending guide rail having a first rolling groove on its outer surface;a slider engaged with the guide rail and having a second rolling groove,rolling element return grooves and curved grooves, the second rollinggroove confronting the first rolling groove, the rolling element returngrooves being coupled to both end portions of the second rolling groovethrough the curved grooves, respectively; a plurality of rollingelements loaded into the slider to be made circulatable through thesecond rolling groove, the curved grooves, and the rolling elementreturn grooves; a lubricant-containing polymer member formed of asynthetic resin containing a lubricant, and having a contact portioncontacting with the guide rail to surround the guide rail, wingportions, and a connecting portion connecting the wing portions to beC-shaped substantially; and a first plate member fitted to thelubricant-containing polymer member, wherein the lubricant-containingpolymer member is interposed between the slider and the first platemember, wherein said lubricant-containing polymer member is a memberseparate from said first plate member.
 2. The linear guide apparatus ofclaim 1, wherein the first plate member comprises a side seals.
 3. Thelinear guide apparatus recited in claim 2, wherein saidlubricant-containing polymer member supplies the lubricant to said sideseal.
 4. The linear guide apparatus recited in claim 1, wherein saidfirst plate member and said lubricant-containing polymer member directlycontact each other.
 5. The linear guide apparatus of claim 1, whereinthe lubricant-containing polymer member is formed of polyolefinicpolymer containing the lubricant of 20 to 80% by weight.
 6. A linearguide apparatus comprising: an axially extending guide rail having afirst rolling groove on its outer surface; a slider engaged with theguide rail and having a second rolling groove, rolling element returngrooves and curved grooves, the second rolling groove confronting thefirst rolling groove, the rolling element return grooves being coupledto both end portions of the second rolling groove through the curvedgrooves, respectively; a plurality of rolling elements loaded into theslider to be made circulatable through the second rolling groove, thecurved grooves, and the rolling element return grooves; a sealing devicefixed to the slider in slidable contact with the guide rail for sealinga clearance existing between the guide rail and the slider, wherein saidsealing device comprises a side seal directly or indirectly fixed to theslider and having a seal lip contacting with the guide rail; and alubricant-containing polymer member formed of a synthetic resincontaining a lubricant and disposed close to the seal lip, saidlubricant-containing polymer member supplying the lubricant to said sideseal, wherein said sealing device is a separate member from saidlubricant-containing polymer member.
 7. The linear guide apparatus ofclaim 6, wherein the lubricant-containing polymer member includes acontact portion contacting with the guide rail.
 8. The linear guideapparatus of claim 6, wherein the lubricant-containing polymer member isformed of polyolefinic polymer containing the lubricant of 20 to 80% byweight.
 9. A linear guide apparatus comprising: an axially extendingguide rail having a first rolling groove on its outer surface; a sliderengaged with the guide rail and having a second rolling groove, rollingelement return grooves and curved grooves, the second rolling grooveconfronting the first rolling groove, the rolling element return groovesbeing coupled to both end portions of the second rolling groove throughthe curved grooves, respectively; a plurality of rolling elements loadedinto the slider to be made circulatable through the second rollinggroove, the curved grooves, and the rolling element return grooves; alubricant-containing member having a contact portion contacting with theguide rail; and a first plate member fitted to the lubricant-containingmember, wherein the lubricant-containing member is interposed betweenthe slider and the first plate member wherein said lubricant-containingmember is a member separate from said first plate member; and whereinthe lubricant-containing member is formed of polyolefinic polymercontaining 20 to 80% lubricant by weight.
 10. A linear guide apparatuscomprising: an axially extending guide rail having a first rollinggroove on its outer surface; a slider engaged with the guide rail andhaving a second rolling groove, rolling element return grooves andcurved grooves, the second rolling groove confronting the first rollinggroove, the rolling element return grooves being coupled to both endportions of the second rolling groove through the curved grooves,respectively; a plurality of rolling elements loaded into the slider tobe made circulatable through the second rolling groove, the curvedgrooves, and the rolling element return grooves; a lubricant-containingmember having a contact portion contacting with the guide rail; and afirst plate member fitted to the lubricant-containing member, whereinthe lubricant-containing member is interposed between the slider and thefirst plate member wherein said lubricant-containing member is a memberseparate from said first plate member; and said linear guide apparatusfurther comprising: a second plate member interposed between the sliderand the lubricant-containing member.
 11. The linear guide apparatus ofclaim 10, wherein at least one of the first plate member and the secondplate member comprises a side seal.
 12. A linear guide apparatuscomprising: an axially extending guide rail having a first rollinggroove on its outer surface; a slider engaged with the guide rail andhaving a second rolling groove, rolling element return grooves andcurved grooves, the second rolling groove confronting the first rollinggroove, the rolling element return grooves being coupled to both endportions of the second rolling groove through the curved grooves,respectively; a plurality of rolling elements loaded into the slider tobe made circulatable through the second rolling groove, the curvedgrooves, and the rolling element return grooves; a lubricant-containingmember having a contact portion contacting with the guide rail; and afirst plate member fitted to the lubricant-containing member, whereinthe lubricant-containing member is interposed between the slider and thefirst plate member wherein said lubricant-containing member is a memberseparate from said first plate member; wherein said lubricant-containingmember further comprises: wing portions; and a connecting portionconnecting the wing portions that forms a substantially C-shape; andwherein said lubricant-containing member comprises a recess or a throughhole, and said linear guide apparatus further comprises a cylindricalmember inserted into the recess or the through hole.
 13. A linear guideapparatus comprising: an axially extending guide rail having a firstrolling groove on its outer surface; a slider engaged with the guiderail and having a second rolling groove, rolling element return groovesand curved grooves, the second rolling groove confronting the firstrolling groove, the rolling element return grooves being coupled to bothend portions of the second rolling groove through the curved grooves,respectively; a plurality of rolling elements loaded into the slider tobe made circulatable through the second rolling groove, the curvedgrooves, and the rolling element return grooves; a lubricant-containingmember having a contact portion contacting with the guide rail; and afirst plate member fitted to the lubricant-containing member, whereinthe lubricant-containing member is interposed between the slider and thefirst plate member wherein said lubricant-containing member is a memberseparate from said first plate member; wherein said lubricant-containingmember further comprises: wing portions; and a connecting portionconnecting the wing portions that forms a substantially C-shape; andwherein the wing portions and the connecting portion form an openingthat is deformed so that the lubricant-containing member closelycontacts the guide rail.
 14. A linear guide apparatus comprising: anaxially extending guide rail having a first rolling groove on its outersurface; a slider engaged with the guide rail and having a secondrolling groove, rolling element return grooves and curved grooves, thesecond rolling groove confronting the first rolling groove, the rollingelement return grooves being coupled to both end portions of the secondrolling groove through the curved grooves, respectively; a plurality ofrolling elements loaded into the slider to be made circulatable throughthe second rolling groove, the curved grooves, and the rolling elementreturn grooves; a lubricant-containing member having a contact portioncontacting with the guide rail; and a first plate member fitted to thelubricant-containing member, wherein the lubricant-containing member isinterposed between the slider and the first plate member wherein saidlubricant-containing member is a member separate from said first platemember; wherein said lubricant-containing member further comprises: wingportions; and a connecting portion connecting the wing portions thatforms a substantially C-shape; and wherein said lubricant-containingmember comprises a pair of first recesses formed in the wing portions,respectively, and said linear guide apparatus further comprises a pairof first cylindrical members inserted into the first recesses,respectively.
 15. The linear guide apparatus of claim 14, wherein thelubricant-containing member includes a second recess formed in theconnecting portion, and said linear guide apparatus comprises a secondcylindrical member inserted into the second recess, the secondcylindrical member having an outer diameter larger than an innerdiameter of the second recess.
 16. The linear guide apparatus of claim15, wherein the second cylindrical member has an axial length largerthan a thickness of the lubricant-containing polymer member.
 17. Thelinear guide apparatus of claim 14, wherein each of the firstcylindrical members has an axial length larger than a thickness of thelubricant-containing polymer member.
 18. The linear guide apparatus ofclaim 14, wherein each of the first cylindrical members has a ringshape.
 19. A linear guide apparatus comprising: an axially extendingguide rail having a first rolling groove on its outer surface; a sliderengaged with the guide rail and having a second rolling groove, rollingelement return grooves and curved grooves, the second rolling grooveconfronting the first rolling groove, the rolling element return groovesbeing coupled to both end portions of the second rolling groove throughthe curved grooves, respectively; a plurality of rolling elements loadedinto the slider to be made circulatable through the second rollinggroove, the curved grooves, and the rolling element return grooves; alubricant-containing member having a contact portion contacting with theguide rail; and a first plate member fitted to the lubricant-containingmember, wherein the lubricant-containing member is interposed betweenthe slider and the first plate member wherein said lubricant-containingmember is a member separate from said first plate member; and whereinthe lubricant-containing member has an elastic member to press againstthe guide rail.
 20. The linear guide apparatus of claim 19, wherein theelastic member extends along the contact portion, the elastic memberbeing fitted close to the contact portion.
 21. A linear guide apparatuscomprising: an axially extending guide rail having a first rollinggroove on its outer surface; a slider engaged with the guide rail andhaving a second rolling groove, rolling element return grooves andcurved grooves, the second rolling groove confronting the first rollinggroove, the rolling element return grooves being coupled to both endportions of the second rolling groove through the curved grooves,respectively; a plurality of rolling elements loaded into the slider tobe made circulatable through the second rolling groove, the curvedgrooves, and the rolling element return grooves; a lubricant-containingmember having a contact portion contacting with the guide rail; and afirst plate member fitted to the lubricant-containing member, whereinthe lubricant-containing member is interposed between the slider and thefirst plate member wherein said lubricant-containing member is a memberseparate from said first plate member; and wherein said slider furthercomprises a bolt for supporting said lubricant-containing memberrelative to said slider, and wherein said lubricant-containing memberfurther comprises both wing portions, and a connecting portionconnecting the wing portions that forms a substantially C-shape, andsaid lubricant-containing member having a recess or a through-holethrough which said bolt passes.